Method of removing water from hydrofluorocarbon manufacturing processes

Abstract

Disclosed are improved fluorination processes and fluorine-containing compositions which involve introducing to one or more fluorination process compositions a water reactive agent in an amount and under conditions effective to decrease the amount of water in that composition. The water reactive agent is preferably introduced to the fluorination process at a location downstream of the fluorination reaction, in amounts and under conditions effective to produce a relatively lower concentration of water in the composition, and preferably throughout the fluorination process.

What is claimed is:  
     
       1. A method of removing water from a fluorination process comprising: 
       a) providing at least one water reactive agent comprising a compound having the formula I:  
       
         
           XR 2   (I)  
         
       
        where  
       X is O═C or O═S, and  
       each R is independently H, alkyl, or halogen, provided that at least one R is halogen  
       b) providing in said fluorination process a composition containing a reactive organic compound, a fluorination agent and water; and  
       c) introducing said water reactive agent into said composition under conditions effective to substantially reduce the concentration of water in said process.  
     
     
       2. A method of removing water from a fluorination process stream comprising: 
       a) providing a process stream containing an organic compound, hydrogen fluoride, and water;  
       b) introducing into said process stream a compound having the formula I:  
       
         
           XR 2   (I)  
         
       
        where  
       X is O═C or O═S, and  
       each R is independently H, alkyl, or halogen, provided that at least one R is halogen; and  
       c) reacting said compound with said water.  
     
     
       3. The method of  claim 2  wherein X is O═C. 
     
     
       4. The method of  claim 3  wherein each of said Rs are chlorine. 
     
     
       5. The method of  claim 4  wherein the temperature of said process stream is from about 20° C. to less than about 350° C. 
     
     
       6. The method of  claim 4  wherein the pressure of said process stream is from about 0 psig to about 200 psig. 
     
     
       7. The method of  claim 5  wherein said compound is phosgene. 
     
     
       8. The method of  claim 2  wherein X is O═S. 
     
     
       9. A method of making fluorinated organic compounds comprising the steps of: 
       a.) reacting at least one organic reactive compound under conditions effective to fluorinate said organic reactive compound to produce a reaction effluent stream comprising water; and  
       b.) introducing into said reaction effluent stream a water reactive agent comprising a compound having the formula I:  
       
         
           XR 2   (I)  
         
       
        where  
       X is OC or O═S, and  
       each R is independently H, alkyl, or halogen, provided that at least one R is halogen said water reactive agent being effective under the conditions of said reaction effluent stream to remove at least a substantial portion of said water from said reaction effluent stream. 
     
     
       10. The method of  claim 9  wherein said reacting step a) comprises a catalytic reaction. 
     
     
       11. The method of  claim 10  wherein said reactive organic compound is a chlorinated vinyl compound. 
     
     
       12. The method of  claim 11  wherein said chlorinated vinyl is ethylene having at least one chlorine substituent. 
     
     
       13. The method of  claim 11  wherein said chlorinated vinyl compound comprises tetrachloroethylene. 
     
     
       14. The method of  claim 10  wherein said compound is present in an amount sufficient to produce a compound:water molar ratio of from about 0.5:1 to about 3:1. 
     
     
       15. The method of  claim 10  wherein a substantial portion of any water present in the reaction effluent stream is removed. 
     
     
       16. The method of  claim 10  wherein said reaction step a) comprises reacting said reactive organic compound with hydrogen fluoride in the presence of a fluorination catalyst to form a fluorinated organic compound product stream containing a water by-product. 
     
     
       17. The method of  claim 16  wherein said reactive organic compound is a chlorinated vinyl compound. 
     
     
       18. The method of  claim 16  wherein said fluorination catalyst comprises chromium. 
     
     
       19. The method of  claim 10  wherein the fluorinated organic compound is a hydrofluorocarbon. 
     
     
       20. The method of  claim 10  wherein the fluorinated organic compound is a hydrochlorofluorocarbon. 
     
     
       21. A method of removing water from a fluorination process of the type having a process stream containing a reactive organic compound, a fluorination agent and water, the method comprising introducing at least one water reactive agent selected from the group consisting of a compound containing a carbonyl group, a thionyl group and combinations of these into said process stream under conditions effective to substantially reduce the concentration of water in said process.